Re: [PATCH v1 1/2] enter.c: Use wmem*() functions with wide-character strings

On Thu, Feb 12, 2026 at 11:56:19PM +0100, Alejandro Colomar via Mutt-dev wrote:
> This avoids an explicit size multiplication, which can overflow the
> calculation.
> 
> Signed-off-by: Alejandro Colomar <[email protected]>
> Cherry-picked-from: neomutt.git 7df621a105e2 (2024-05-09, "Use wmem*() functions with wide-character strings")
> [alx: Adapted diff and message to mutt(1)]
> Signed-off-by: Alejandro Colomar <[email protected]>
> ---
>  enter.c | 27 ++++++++++++++-------------
>  1 file changed, 14 insertions(+), 13 deletions(-)
> 
> diff --git a/enter.c b/enter.c
> index 54e81178b3c5..ba8b9963659c 100644
> --- a/enter.c
> +++ b/enter.c
> @@ -29,6 +29,7 @@
>  #include "buffy.h"
>  
>  #include <string.h>
> +#include <wchar.h>
>  
>  /* redraw flags for mutt_enter_string() */
>  enum
> @@ -175,7 +176,7 @@ static void replace_part (ENTER_STATE *state, size_t from, char *buf)
>    if (savelen)
>    {
>      savebuf = safe_calloc (savelen, sizeof (wchar_t));
> -    memcpy (savebuf, state->wbuf + state->curpos, savelen * sizeof (wchar_t));
> +    wmemcpy (savebuf, state->wbuf + state->curpos, savelen);

If there was going to be an overflow, safe_calloc() would have crashed
the system, so we can "know" that if it returns, it's all good so there
will not be any overflow happening.

So I don't think this patch actually does anything except make code
checking tools happy because it can not actually read the logic :)

thanks,

greg k-h